JP2006070371A - Paper softener - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper softener capable of giving highly pliable paper with high water absorbability and storable for a long period. <P>SOLUTION: The paper softener contains an alkylene oxide derivative (a) and at least one compound (b) selected from the group consisting of a quaternary ammonium compound (b1) and an amine compound (b2), wherein the alkylene oxide derivative (a) is a compound of the formula (1): R<SP>1</SP>O(AO)<SB>x</SB>(BO)<SB>y</SB>(AO)<SB>z</SB>H (wherein, R<SP>1</SP>is an 8-24C alkyl, alkenyl or acyl; A is an ethylene group; B is a butylene group; 0≤x≤15; 1≤y≤5; 0≤z≤40, wherein 15≤(x+z)≤40). This paper softener contains 1-20 mass% of the component (a) and 2-25 mass% of the component (b) with the mass ratio (a)/(b) being (1:10) to (5:1). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a softening agent for paper. More specifically, the present invention relates to a softener for paper that can be flexibly bent and added to the paper product during the manufacturing process to produce paper having excellent water absorption and also has excellent storage stability.

  Paper is used for various purposes in daily life as bookbinding paper such as comic books and paper bags, or as sanitary paper such as toilet paper and tissue paper. In particular, sanitary paper is required to bend flexibly from its application, and many softeners for paper have been developed so far.

  So far, compounds such as glycerin, paraffin emulsions, quaternary ammonium salts have been used as softening agents for paper, but with these compounds, the flexibility of paper, that is, the flexibility of bending, is insufficient, There was a drawback that the water absorption of the paper was lowered.

  In order to solve the problem of water absorption, for example, a softener (for example, Patent Document 1) containing a di-long-chain alkyl quaternary ammonium salt and glycerin and water or an aliphatic alcohol having 4 or less carbon atoms, Softeners containing lanolin and lanolin derivatives (for example, Patent Document 2), softeners containing urethane alcohol or a quaternized product thereof (for example, Patent Document 3), softeners containing pyrrolidone carboxylic acid or a salt thereof (for example, Patent Documents) 4) A softener (for example, Patent Document 5) containing an ester compound of fatty acid and pentaerythritol and a mixture of fatty acids is known.

Although these paper softeners improve water absorption to some extent, bending flexibility (ease of paper bending), which is particularly problematic when using sanitary paper in layers, is still not improved. Furthermore, none of the above-mentioned softening agents for paper has a problem that the storage stability is sufficient, the viscosity increases with time, or solidification or separation occurs during low-temperature storage.
Japanese Patent Laid-Open No. 4-100995 JP-A-53-147803 JP-A-60-139897 JP-A-7-189170 JP 7-189171 A

  An object of the present invention is to provide a softener for paper which can be flexibly bent and can obtain a paper excellent in water absorption, which can be stored for a long time.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have used a paper softening agent in which a specific alkylene oxide derivative having butylene oxide in the molecule and a quaternary ammonium salt or an amine compound are combined. The present invention has been completed by finding that a paper that flexes flexibly and has excellent water absorption can be obtained, and that the softener for paper has excellent storage stability.

The paper softener of the present invention contains a paper containing an alkylene oxide derivative (a) and at least one compound (b) selected from the group consisting of a quaternary ammonium compound (b1) and an amine compound (b2). A softener for use in which the alkylene oxide derivative (a) is a compound represented by the formula (1):
R ¹ O (AO) _x (BO) _y (AO) _z H (1)
Wherein R ¹ is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an acyl group, A is an ethylene group, B is a butylene group, and 0 ≦ x ≦ 15, 1 ≦ y ≦ 5, (0 ≦ z ≦ 40, 15 ≦ x + z ≦ 40)
In the softener for paper, 1 to 20% by mass of (a) and 2 to 25% by mass of (b) are contained, and the mass ratio between (a) and (b) ( It is contained so that a) / (b) is 1/10 to 5/1.

  In a preferred embodiment, the quaternary ammonium compound (b1) is a quaternary ammonium salt represented by the formula (2) or a quaternary ammonium salt represented by the formula (3):

Wherein R ² and R ³ are each an alkyl or alkenyl group having 10 to 24 carbon atoms, R ⁴ is an alkyl or benzyl group having 1 to 3 carbon atoms, m is 1 to 10 and X ⁻ is an anion),

Wherein R ⁵ CO and R ⁶ CO are each an acyl group having 10 to 24 carbon atoms, R ⁷ , R ⁹ and R ¹⁰ are each an alkylene group having 1 to 3 carbon atoms, and R ⁸ Is an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ⁻ is an anion).

In a preferred embodiment, the amine compound (b2) comprises a carboxylic acid having 10 to 24 carbon atoms and a polyalkylene polyamine represented by the formula (4) in a molar ratio of 1.5: 1 to 2.5: 1. An amidoamine compound or a salt thereof obtained by reacting with:
^{_{NH 2 -R 11 - (NH-}} R 12) n -NH 2 (4)
(In the formula, R ¹¹ and R ¹² are each an alkylene group having 1 to 4 carbon atoms, and n is an integer of 1 to 3).

  According to the present invention, by using a paper softener that is a combination of a specific alkylene oxide derivative having butylene oxide in the molecule and a quaternary ammonium salt or an amine compound, a paper that flexes flexibly and has excellent water absorption can be obtained. can get. The paper softener of the present invention is further excellent in storage stability.

  The paper softener of the present invention contains an alkylene oxide derivative (a) and at least one compound (b) selected from the group consisting of a quaternary ammonium compound (b1) and an amine compound (b2), If necessary, it may contain other components (component c) such as a solvent.

(Alkylene oxide derivative (a))
The alkylene oxide derivative (a) (hereinafter sometimes referred to as “component a”) contained in the paper softener of the present invention is a compound represented by the formula (1):
R ¹ O (AO) _x (BO) _y (AO) _z H (1)
Wherein R ¹ is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an acyl group, A is an ethylene group, B is a butylene group, and 0 ≦ x ≦ 15, 1 ≦ y ≦ 5, 0 ≦ z ≦ 40 and 15 ≦ x + z ≦ 40).

In the compound represented by the formula (1), R ¹ is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an acyl group as described above. Specific examples include the following groups: octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, isoundecyl, dodecyl, isododecyl, tridecyl, isotridecyl, tetradecyl, Isotetradecyl group, pentadecyl group, isopentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, isoheptadecyl group, octadecyl group, isooctadecyl group, nonadecyl group, isononadecyl group, eicosyl group, isoeicosyl group, heneicosyl group, iso Alkyl groups such as heneicosyl group, docosyl group, isodocosyl group, tricosyl group, isotricosyl group, tetracosyl group, isotetracosyl group;
Alkenyl groups such as tetradecenyl group, hexadecenyl group, octadecenyl group, eicosenyl group, dococenyl group; and octanoyl group, decanoyl group, dodecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, eicosanoyl group, docosanoyl group, Acyl groups such as tetracosanoyl group, 2-ethylhexanoyl group, hexadecenoyl group and octadecenoyl group. Among these, an alkyl group having 10 to 22 carbon atoms, an alkenyl group, and an acyl group are preferable, and an acyl group is more preferable.

  When the number of carbon atoms is less than 8, the paper has insufficient water absorption. When the number of carbon atoms exceeds 24, handling of the alkylene oxide derivative may be difficult, and the storage stability of the resulting paper softener is poor. Furthermore, the water absorption of the paper obtained using the paper softener is insufficient.

  In the compound represented by formula (1), x, y, and z represent the average number of moles added. x is 0-15, preferably 0-8. When x exceeds 15, even if the obtained paper softener is used, sufficient bending flexibility and water absorption cannot be imparted to the paper. y is 1 to 5, preferably 1 to 3. When y exceeds 5, the storage stability of the resulting paper softener is poor, and the water absorption of the paper obtained using the paper softener is insufficient. When y is less than 1, the water absorption of the paper is insufficient. z is 0-40, preferably 0-30. Furthermore, x + z is 15-40, preferably 18-30. When z exceeds 40 or x + z exceeds 40, sufficient flexibility and water absorption cannot be imparted to the paper even if the obtained paper softener is used. When x + z is less than 15, the storage stability of the resulting paper softener is poor, and the water absorption of the paper obtained using the paper softener is insufficient.

  Specifically, the alkylene oxide derivative (a) is prepared by first adding butylene oxide to an alcohol or a fatty acid in the presence of an alkali catalyst to add ethylene oxide, or after adding ethylene oxide, adding butylene oxide, and further adding ethylene oxide. It is obtained by adding.

(Compound (b))
The compound (b) (hereinafter sometimes referred to as “component b”) is a quaternary ammonium compound (b1) and / or an amine compound (b2). That is, these compounds may be used alone or in combination.

(Quaternary ammonium compound (b1))
Examples of the quaternary ammonium compound (b1) include an alkyl quaternary ammonium salt represented by the formula (5), an ester quaternary ammonium salt represented by the formula (6), and an amide type 4 represented by the formula (7). Examples include quaternary ammonium salts and imidazolinium-type quaternary ammonium salts represented by the formula (8).

(Wherein R ¹³ is an alkyl group or alkenyl group having 10 to 24 carbon atoms; R ¹⁴ and R ¹⁵ are each an alkyl group or alkenyl group having 10 to 24 carbon atoms, or each having 1 to 3 carbon atoms) An alkyl group, a hydroxyalkyl group, a benzyl group, or — (CH ₂ CH ₂ O) _p H (p: 1 to 10); R ¹⁶ is an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, benzyl A group or — (CH ₂ CH ₂ O) _pH (p: is 1 to 10); and X ⁻ is an anion).

(Wherein R ¹⁷ CO is an acyl group having 10 to 24 carbon atoms; R ¹⁸ is R ¹⁷ CO—OR ²¹ , an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, or — (CH ₂ CH ₂ O) _p H (p: 1 to 10); R ¹⁹ is R ¹⁷ CO-OR ²¹ , an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, or — (CH ₂ CH ₂ O) _p H (p: 1 to 10); R ²⁰ is an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, a benzyl group or — (CH ₂ CH ₂ O) _p H (p: 1). R ²¹ is an alkylene group having 1 to 3 carbon atoms; and X ⁻ is an anion).

Wherein R ²² and R ²³ are each an acyl group having 10 to 24 carbon atoms; R ²⁴ and R ²⁵ are each an alkylene group having 1 to 3 carbon atoms; and R ²⁶ and R ²⁷ are each alkyl group having 1 to 3 carbon atoms, hydroxyalkyl group, benzyl group, or _{- (CH 2 CH 2 O)} p H: a (p 1 to 10 a is)).

Wherein R ²⁸ is an alkyl or alkenyl group having 10 to 24 carbon atoms; R ²⁹ is an alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, a benzyl group, or — (CH ₂ CH ₂ O) _p H (p: 1 to 10); R ³⁰ is an acyl group having 10 to 24 carbon atoms).

  Among these, the quaternary ammonium salt (alkyl quaternary ammonium salt) represented by the following formula (2) or the quaternary ammonium salt (ester quaternary ammonium salt) represented by the formula (3) is applied to the paper. Furthermore, it is preferable at the point which obtains the softener for paper which gives a favorable water absorption.

Wherein R ² and R ³ are each an alkyl or alkenyl group having 10 to 24 carbon atoms, R ⁴ is an alkyl or benzyl group having 1 to 3 carbon atoms, m is 1 to 10 and X ⁻ is an anion),

Wherein R ⁵ CO and R ⁶ CO are each an acyl group having 10 to 24 carbon atoms, R ⁷ , R ⁹ and R ¹⁰ are each an alkylene group having 1 to 3 carbon atoms, and R ⁸ Is an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ⁻ is an anion).

In the quaternary ammonium salt represented by the formula (2), R ² and R ³ are each an alkyl group or alkenyl group having 10 to 24 carbon atoms. Specific examples include the following groups: decyl, undecyl, dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl Groups, alkyl groups such as henicosyl group, docosyl group; and alkenyl groups such as tetradecenyl group, hexadecenyl group, octadecenyl group, dococenyl group. Among these, a C12-22 alkyl group and an alkenyl group are preferable.

In the quaternary ammonium salt represented by the formula (2), R ⁴ is an alkyl group having 1 to 3 carbon atoms or a benzyl group, and examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, a propyl group, An isopropyl group etc. are mentioned. A methyl group or an ethyl group is preferable.

  In the quaternary ammonium salt represented by the formula (2), m is 1 to 10 as described above, which corresponds to the number of added moles of ethylene oxide. m is preferably 1-7.

In the quaternary ammonium salt represented by the formula (2), X ⁻ is an anion, and examples thereof include fluorine ion, chlorine ion, bromine ion, iodine ion, methyl sulfate ion, and ethyl sulfate ion. Chlorine ion or methyl sulfate ion is preferred.

In the quaternary ammonium salt represented by the formula (3), R ⁵ CO and R ⁶ CO are specifically acyl groups derived from carboxylic acids having 10 to 24 carbon atoms, such as capric acid, lauric acid, Lindel Acid, myristic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, arachidic acid, eicosenoic acid, behenic acid, erucic acid, lignoceric acid, ceracolonic acid Acyl group derived from carboxylic acid such as: palm oil fatty acid, palm oil fatty acid, beef tallow fatty acid, pork tallow fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, tall oil fatty acid, cocoa oil fatty acid, sesame oil fatty acid, corn oil fatty acid, sunflower Mixed fatty acids derived from natural fats and oils such as oil fatty acids and cottonseed oil fatty acids, and Examples include acyl groups derived from these hydrogenated products. Different R ⁵ CO or R ⁶ CO groups may be present in one molecule, and two or more quaternary ammonium salts represented by the formula (3) can be used.

In the quaternary ammonium salt represented by the formula (3), R ⁷ , R ⁹ , and R ¹⁰ are each an alkylene group having 1 to 3 carbon atoms, specifically, a methylene group, an ethylene group, and a propylene group. Is mentioned. An ethylene group is preferred.

In the quaternary ammonium salt represented by the formula (3), R ⁸ is an alkyl group having 1 to 3 carbon atoms or a benzyl group. Specific examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, A propyl group, an isopropyl group, etc. are mentioned. A methyl group or an ethyl group is preferable.

In the quaternary ammonium salt represented by the formula (3), X ⁻ is an anion, and examples thereof include fluorine ion, chlorine ion, bromine ion, iodine ion, methyl sulfate ion, and ethyl sulfate ion. Chlorine ion or methyl sulfate ion is preferred.

  Any of these quaternary ammonium salts (b1) can be produced by methods commonly used by those skilled in the art.

(Amine compound (b2))
Examples of the amine compound (b2) include alkylamines having 10 to 24 carbon atoms or alkenyl groups, dialkylamines, and alkylpolyamines; and amidoamine compounds. These amine compounds may be in the form of a salt. Preferably, it is an amidoamine compound or a salt thereof.

The amidoamine compound is obtained by reacting a carboxylic acid having 10 to 24 carbon atoms with an alkyl polyamine or polyalkylene polyamine having 2 to 5 amino groups in one molecule. Further, from the viewpoint of obtaining paper having good bending flexibility, an amidoamine compound obtained by reacting a carboxylic acid having 10 to 24 carbon atoms with a polyalkylene polyamine represented by the formula (4) is more preferable:
^{_{NH 2 -R 11 - (NH-}} R 12) n -NH 2 (4)
(In the formula, R ¹¹ and R ¹² are each an alkylene group having 1 to 4 carbon atoms, and n is an integer of 1 to 3).

  The carboxylic acid having 10 to 24 carbon atoms used for the preparation of the amidoamine compound may be either a saturated carboxylic acid or an unsaturated carboxylic acid, or a linear carboxylic acid or a branched carboxylic acid. May be. Examples of such carboxylic acids include capric acid, lauric acid, Linderic acid, myristic acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, elaidic acid, Arachinic acid, eicosenoic acid, behenic acid, erucic acid, lignoceric acid, ceracolonic acid, mixtures thereof; coconut oil fatty acid, palm oil fatty acid, beef tallow fatty acid, tallow fatty acid, soybean oil fatty acid, rapeseed oil fatty acid, tall oil fatty acid, olive oil fatty acid , Mixed fatty acids derived from natural fats and oils such as cacao oil fatty acid, sesame oil fatty acid, corn oil fatty acid, sunflower oil fatty acid and cottonseed oil fatty acid, and hydrogenated products thereof. Among these, a carboxylic acid having 12 to 22 carbon atoms is preferable, and a carboxylic acid having 14 to 18 carbon atoms is more preferable. In the case of a carboxylic acid having less than 10 carbon atoms, even if the obtained paper softener is used, sufficient bending flexibility may not be imparted to the paper. When the carboxylic acid has more than 24 carbon atoms, it may be difficult to handle the amidoamine compound, and even if a paper softener obtained from the amidoamine compound is used, the water absorption of the paper may be insufficient.

  The carboxylic acid preferably contains 40% by mass or more of unsaturated carboxylic acid and / or carboxylic acid having a branched chain. By using a paper softener obtained from such a carboxylic acid, paper having good water absorption can be obtained. Natural mixed fatty acids containing 40 to 100% by weight of unsaturated carboxylic acid include soybean oil fatty acid, palm oil fatty acid, olive oil fatty acid, cocoa oil fatty acid, sesame oil fatty acid, corn oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, beef tallow fatty acid And pork fat fatty acid. More preferred are soybean oil fatty acid, oleic acid, and erucic acid.

As the polyalkylene polyamine which is a raw material of the amidoamine compound, a compound represented by the formula (4) is preferably used. In the compound represented by the formula (4), R ¹¹ and R ¹² are each an alkylene group having 1 to 4 carbon atoms, specifically a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a butylene group, Examples thereof include a mixture of two or more of these. An ethylene group is preferred. When the number of carbon atoms of the alkylene group exceeds 4, it is difficult to handle the resulting amidoamine compound.

  The amidoamine compound used in the paper softener of the present invention comprises a carboxylic acid having 10 to 24 carbon atoms and a polyalkylene polyamine represented by the formula (4) in a molar ratio of 1.5: 1 to 2.5: 1. It is preferable that it is obtained by reacting at a molar ratio of 1.8: 1 to 2.2: 1. When the amount of the carboxylic acid is less than 1.5 moles relative to 1 mole of the polyalkylene polyamine represented by the formula (4), a paper having sufficient bending flexibility can be obtained even if the obtained paper softener is used. In some cases, when it exceeds 2.5 moles, it may be difficult to handle the amidoamine compound.

  The ratio of tertiary amine value / total amine value of the amidoamine compound used in the present invention is preferably 0.6 to 0.99, and preferably 0.70 to 0.99. When a paper softener obtained from such an amidoamine compound is used, paper with better bending flexibility can be obtained.

  An amidoamine compound having a tertiary amine value / total amine value ratio of 0.6 to 0.99 is obtained as follows. When the carboxylic acid is reacted with the polyalkylene polyamine of formula (4), the amidation reaction in which the carboxylic acid reacts with the amino group until the acid value of the reaction mixture reaches about 10% of the theoretical acid value at the time of charging. Proceeds preferentially to produce a compound having a ratio of tertiary amine value to total amine value of 0 to 0.4. However, when the acid value of the reaction mixture is less than 10% of the theoretical acid value at the time of charging, the decrease in the acid value with respect to the reaction time becomes small, and thus the normal amidation reaction as described above is completed at this stage. . When the reaction proceeds further under predetermined conditions from this stage, the amide group and amino group of the produced amidoamine compound are dehydrated and condensed to produce an amidoamine compound having a tertiary amine moiety. Therefore, the ratio of the tertiary amine value to the total amine value exceeds 0.4, and it becomes possible to obtain an amidoamine compound having a tertiary amine value / total amine value ratio of 0.6 to 0.99. . Specifically, the above-mentioned amidoamine compound having the tertiary amine value / total amine value ratio is, for example, 75% on the basis of the acid value at the stage when it becomes 10% or less of the theoretical acid value when the reaction mixture is charged. It can be obtained by proceeding the reaction until the acid value falls to less than 1%. The method of proceeding such a reaction (reaction in which the amide group and amino group of the amidoamine compound are dehydrated and condensed) is not particularly limited, but a method of performing a reduced pressure reaction after the formation of the amidoamine compound or a reaction at a higher temperature The method of performing etc. is mentioned.

  The amine compound used in the present invention can be used as it is for a softener for paper, but if it is neutralized with an inorganic acid or an organic acid and used as a salt, it is easy to handle and easy to use. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, carbonic acid, nitric acid, and phosphoric acid. Organic acids include formic acid, acetic acid, propionic acid, octylic acid, butyric acid, oxalic acid, malonic acid, itaconic acid, adipic acid, succinic acid, sebacic acid, citric acid, hydroxybenzoic acid, malic acid, hydroxymalonic acid, lactic acid , Salicylic acid, hydroxyvaleric acid, aspartic acid, glutamic acid, taurine, sulfamic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and the like. Among these, organic acids are preferable, and formic acid, acetic acid, and lactic acid are more preferable.

  The amount of the acid used to form the salt may be determined appropriately according to the purpose by measuring the total amine value of the amine compound. It is preferable to add an inorganic acid or an organic acid so as to be equivalent to the total amine value.

(Other ingredients)
Examples of other components used in the present invention include a solvent. Although the kind of the said solvent is not specifically limited, From the point which improves the storage stability of the softener for paper, water-soluble 1-3 hydric alcohol (c component) is used suitably. Examples of such water-soluble 1 to 3 alcohols include ethanol, 1-propanol, isopropanol, 1-butanol, t-butanol, 3-methoxy-3-methyl-butanol, propylene glycol, dipropylene glycol, 2 -Methyl-1,3-propanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, glycerin, polyethylene glycol having a molecular weight of 150 to 600, and the like. Of these, 3-methoxy-3-methyl-butanol, propylene glycol, and polyethylene glycol having a molecular weight of 150 to 600 are preferably used. These alcohols may be used alone or in combination of two or more.

(Softener for paper)
The paper softener of the present invention comprises at least one compound (b) selected from the group consisting of the alkylene oxide derivative (a) (component a), a quaternary ammonium compound (b1), and an amine compound (b2). (Component b) and may contain other components such as a solvent, if necessary.

  The softener for paper of the present invention contains 1 to 20% by mass of component a, preferably 3 to 18% by mass, and 2 to 25% by mass, and preferably 5 to 20% by mass of component b. The paper softener with a component a content of less than 1% by weight has insufficient water absorbability of the paper obtained, and the paper softener with a content of more than 20% by weight has poor flexibility in bending the paper obtained. It is enough. On the other hand, the softening agent for paper having a content of component b of less than 2% by mass is insufficient in the flexibility of bending of the obtained paper, and the softening agent for paper exceeding 25% by mass has poor storage stability.

  The mass ratio (component a / component b) of component a and component b contained in the paper softener of the present invention is 1/10 to 5/1, preferably 1/8 to 3/1. . When a / b is less than 1/10, the storage stability of the paper softener is poor, and the water absorption of the paper obtained using this paper softener is insufficient. When a / b exceeds 5/1, this paper softener is insufficient in the flexibility of bending of the obtained paper.

  The paper softener of the present invention is used in paper production. Specifically, in the paper manufacturing process, the paper softener is added so that the total amount of the component a and component b is 0.03 to 8 parts by mass with respect to 100 parts by mass of the pulp raw material. It is preferable from the point of being able to obtain a paper that bends flexibly and has excellent water absorption and is economical. Examples of the raw material pulp include chemical pulp (conifer or hardwood bleached or unbleached kraft pulp), mechanical pulp (ground pulp, thermomechanical pulp, chemithermomechanical pulp, etc.), deinked pulp (newspaper, magazine waste paper, etc.), etc. Is mentioned. These raw pulps can be used alone or mixed at an arbitrary ratio.

  Further, the paper softener of the present invention comprises various additive agents generally used in the papermaking process, for example, paper strength enhancers such as polyacrylamide and plant guam; sizing agents such as alkyl ketene dimer and rosin; polyethyleneimine Freeness / yield improvers such as cationized polymers; internal additives such as sulfate bands, sodium chloride, sodium aluminate, polyvinyl alcohol, latex; pitch control agents, slime control agents, etc., if necessary Can do.

  The paper softener of the present invention can be used in all paper machines such as a long paper machine, a twin wire machine, and a Yankee machine. Furthermore, it can be added in any case of internal addition added to the pulp slurry in processes such as mixing test, machine chest, and seed box, and external addition such as size press and gate roll applied to the paper pulp sheet. .

  Paper obtained by using the paper softener of the present invention bends flexibly and has excellent water absorption. Such paper is suitably used especially for sanitary thin paper such as toilet paper, dust paper, facial tissue, Kyoto flower paper, paper napkin, paper towel, wiper, sanitary paper, diaper paper and the like.

  The present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(1) Preparation of alkylene oxide derivative (component a) (Synthesis Example 1.1)
400 g (2.0 mol) of lauric acid and 20 g of potassium hydroxide (5 parts by mass with respect to 100 parts by mass of carboxylic acid) were weighed in a 10 L autoclave, heated to 125 ° C., and 187.3 g (2.6 of butylene oxide) (2.6 Mol) was reacted under the condition of 0.49 MPa, and aging was performed for 2 hours (hydroxyl value 200.1, butylene oxide average added mole number 1.1). Further, 3737.2 g (72.2 mol) of ethylene oxide was reacted under the condition of 0.49 MPa, and aging was performed for 2 hours. Next, after degassing under reduced pressure at 75 ° C., the mixture was neutralized with acetic acid and filtered to obtain a hydroxyl value of 30.8 mgKOH / g, butylene oxide average addition mole number 1.1, and ethylene oxide average addition mole number. An alkylene oxide derivative of 35.0 was obtained.

(Synthesis Examples 1.2 to 1.6)
In the same manner as in Synthesis Example 1.1, an alkylene oxide derivative having an average addition mole number (x, y, z) and a composition of R ¹ shown in Table 1 was obtained.

  As shown in Table 1, the alkylene oxide derivatives obtained in Synthesis Examples 1.1 to 1.3 are compounds (component a) represented by the formula (1) (these are alkylene oxide derivatives a-1 to a- 3). On the other hand, the alkylene oxide derivatives a-4 to a-6 obtained in Synthesis Examples 1.4 to 1.6 do not satisfy the formula (1). That is, the alkylene oxide derivative of Synthesis Example 1.4 does not satisfy 15 ≦ x + z ≦ 40, the alkylene oxide derivative of Synthesis Example 1.5 does not satisfy 1 ≦ y ≦ 5, and the alkylene oxide derivative of Synthesis Example 1.6. The derivative does not satisfy 0 ≦ z ≦ 40.

(2) Preparation of quaternary ammonium compound (component b1) Among the quaternary ammonium salts (component b1) used in the examples described later, the following commercially available products are used for b-1 and b-2. -3 was synthesized as shown in Synthesis Example 2.1. These quaternary ammonium compounds b-1 to b-3 are shown in Table 2.

b-1: Cation 2ABT (di-tallow alkyl dimethyl ammonium chloride: manufactured by Nippon Oil & Fats Co., Ltd.)
b-2: Cation 20L-205 (names of groups corresponding to the respective groups of formula (3) are shown in Table 2: manufactured by NOF Corporation)

(Synthesis Example 2.1)
A four-necked flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen inlet tube was charged with 340.0 g (1.0 mol) of erucic acid and 74.5 g (0.5 mol) of triethanolamine under a nitrogen atmosphere. The mixture was heated to 180 ° C. and reacted for 15 hours at 180 ° C. while removing water out of the system to obtain an ester compound having a hydroxyl value of 71.5 and a total amine value of 69.4. After charging 323.3 g (0.4 mol) of this ester compound and 370.0 g of ethanol into a reaction vessel equipped with a stirrer and a thermometer, the gas phase was purged with nitrogen at 60 ° C., and then dimethyl at 70 ° C. with stirring. 50.1 g (0.4 mol) of sulfuric acid was reacted for 2 hours to obtain a quaternary ammonium salt b-3 having a total amine value of less than 0.1.

(3) Preparation of amine compound (component b2) According to the following synthesis examples 3.1 to 3.3, salts b-4 to b-6 of amine compounds shown in Table 3 below were prepared. In Synthesis Examples 3.1 to 3.3, the fatty acids of beef tallow fatty acid, oleic acid, and soybean oil fatty acid used are all carboxylic acids having 10 to 24 carbon atoms, and the composition (mass%) is as follows. As follows:
Tallow fatty acid: myristic acid (3.0%), palmitic acid (24.8%), stearic acid (16.1%), myristoleic acid (1.5%), palmitoleic acid (4.7%), olein Acid (41.8%), linoleic acid (3.9%), linolenic acid (1.0%), others (3.2%);
Oleic acid: palmitic acid (2.0%), stearic acid (1.5%), palmitoleic acid (2.0%), oleic acid (91.0%), linoleic acid (2.0%), others ( 1.5%); and soybean oil fatty acids: palmitic acid (11.6%), stearic acid (4.2%), oleic acid (33.3%), linoleic acid (42.2%), linolenic acid ( 7.2%) and others (1.5%).

(Synthesis Example 3.1)
A 500 mL four-necked flask equipped with a stirrer, cooling tube, thermometer and nitrogen inlet tube was charged with 276.3 g (1 mol) of beef tallow fatty acid and heated to 90 ° C. with stirring under a nitrogen atmosphere. Diethylenetriamine 51.5 g (0.5 mol) was charged, and the reaction was carried out at 180 ° C. for 2 hours while removing water out of the system. An amidoamine compound having an acid value of 3.2, a total amine value of 90.8, a tertiary amine value of 26.3 (ratio of the tertiary amine value to the total amine value of 0.29) was obtained. Next, 60 g of the obtained compound and 5.8 g of equimolar acetic acid with respect to the total amine value were charged into a 100 mL capacity beaker to prepare amidoamine compound salt b-4.

(Synthesis Example 3.2)
The acid value was the same as in Synthesis Example 3.1 except that 1 mole (282.5 g) of oleic acid was used instead of beef tallow fatty acid and 0.5 mole of triethylenetetramine was used instead of diethylenetriamine. 3.2 Amidoamine compound salt b-5 having a total amine value of 152.2, a tertiary amine value of 54.4 (ratio of tertiary amine value to total amine value of 0.36) was obtained.

(Synthesis Example 3.3)
Acid value 3.2, total amine value 91.1, tertiary amine value 82, in the same manner as in Synthesis Example 3.1 except that 1 mol (280.5 g) of soybean oil fatty acid was used instead of beef tallow fatty acid. 0.1 (ratio of tertiary amine value to total amine value 0.90) was obtained.

(4) Preparation and evaluation of paper softener (Example 1)
Table 4 shows the proportion of the alkylene oxide derivative a-1 (component a), quaternary ammonium salt b-1 (component b), propylene glycol (component c), and ion-exchanged water obtained in Synthesis Example 1.1. A softener for paper was prepared by mixing at (mass ratio).

Using this paper softener, a test paper was prepared as follows. The softener for paper obtained in Example 1 was added to a pulp slurry obtained by disaggregating LBKP (hardwood bleached pulp) to a concentration of 0.5% so that the dry weight of the pulp was 1.0% by mass. After stirring for a minute, paper with a basis weight of 20 g / m ^{2 was} made with a small inclined short net paper machine (manufactured by Daisho Iron Works Co., Ltd.). The obtained sheet was dried and cut into 20 cm × 20 cm, which was used as a test paper.

  The following items were evaluated for the test paper and the paper softener of Example 1 used for the test paper. The results are shown in Table 4.

(I) Evaluation of bending flexibility The test paper is stored for 48 hours in a constant temperature and humidity chamber at room temperature of 23 ° C. and humidity of 50%. Next, two sheets of this test paper are stacked, and the bending stiffness in the longitudinal direction and the transverse direction is measured using a pure bending tester (KES-FB2 manufactured by Kato Tech Co., Ltd.), and the average value is obtained. The suppleness of the test paper was evaluated from the above average value according to the following criteria:
Flexural rigidity of 3.92 × 10 ⁻⁵ N · m ² / m or more: Insufficient flexibility (×)
Flexural rigidity: 3.43 × 10 ⁻⁵ N · m ² / m or more and less than 3.92 × 10 ⁻⁵ N · m ² / m: Good flexibility (◯)
Flexural rigidity of less than 3.43 × 10 ⁻⁵ N · m ² / m: very flexible (◎).

(Ii) Measurement of water absorption The test paper is stored for 48 hours in a constant temperature and humidity room at room temperature 23 ° C. and humidity 50%. The test paper is then cut into 5.5 × 100 mm pieces of paper. Place 30 mL of ion-exchanged water in a 100 mL capacity beaker, place one end of the test paper in the longitudinal direction down, immerse the 5 mm portion from the bottom in this water, and the amount of water sucked up by the paper piece after 10 minutes (the liquid level) To the upper end of the permeated liquid (mm). The water absorption of the test paper is evaluated according to the following criteria:
Water absorption of less than 40 mm: insufficient water absorption (×)
Water absorption 40 mm or more and less than 50 mm: good water absorption (◯)
Water absorption of 50 mm or more: Water absorption is very good (◎).

(Iii) Evaluation of stability over time of paper softener The paper softener obtained in Example 1 was sealed and allowed to stand at room temperature for 1 month, and the increase in viscosity (thickening) and the presence or absence of layer separation were visually observed. And evaluate according to the following criteria:
○: Thickening and layer separation are not observed in the paper softener ×: Thickening or layer separation is observed in the paper softener.

(Iv) Evaluation of low-temperature storage stability of paper softening agent The paper softening agent obtained in Example 1 was sealed and visually evaluated for the presence or absence of solidification when left in a thermostatic bath at 0 ° C for 1 month. :
○: Paper softener does not solidify ×: Paper softener solidifies

(Examples 2 to 6)
Alkylene oxide derivatives a-1 to a-6 (component a), quaternary ammonium salts b-1 to b-3 or amine compounds b-4 to b-6 (component b) shown in Table 4, water-soluble alcohols ( c component) and ion-exchanged water were mixed at a ratio (mass ratio) shown in Table 4 to prepare a softener for paper. Using these paper softeners, test papers were prepared in the same manner as in Example 1, and the test papers were evaluated and the stability of the paper softeners was evaluated. The results are also shown in Table 4.

(Comparative Examples 1-4)
Alkylene oxide derivatives a-1 to a-6 (component a), quaternary ammonium salts b-1 to b-3 or amine compounds b-4 to b-6 (component b) shown in Table 4, water-soluble alcohols ( c component) and ion-exchanged water were mixed at a ratio (mass ratio) shown in Table 4 to prepare a softener for paper. Using these paper softeners, test papers were prepared in the same manner as in Example 1, and the test papers were evaluated and the stability of the paper softeners was evaluated. The results are also shown in Table 4.

  From the results of Table 4, it can be seen that by using the paper softeners of Examples 1 to 6, paper having good bending flexibility and good water absorption can be obtained. In particular, the papers obtained using the paper softeners of Examples 2 and 3 were excellent in water absorption, and the papers obtained using the paper softeners of Examples 4 to 6 were excellent in bending flexibility. On the other hand, in Comparative Example 1, the content of component b and the mass ratio (a / b) between component a and component b do not satisfy the scope of the present invention, and the water absorption of the resulting paper is insufficient. The paper softeners that do not satisfy the conditions of the alkylene oxide derivatives used in the present invention of Comparative Examples 2 to 4 have problems in the following points. That is, since the alkylene oxide derivative contained in the paper softener of Comparative Example 2 does not have an oxyethylene group (15 ≦ x + z ≦ 40 is not satisfied), the water absorption of the obtained paper was insufficient. Since the alkylene oxide derivative contained in the paper softener of Comparative Example 3 does not have an oxybutylene group (does not satisfy 1 ≦ y ≦ 5), the water absorption of the obtained paper was insufficient. Since the alkylene oxide derivative contained in the paper softener of Comparative Example 4 has a large number of added oxyethylene groups (does not satisfy 0 ≦ z ≦ 40), the resulting paper has poor bending flexibility and water absorption. It was enough.

  ADVANTAGE OF THE INVENTION According to this invention, the softening agent for papers which can bend flexibly and can obtain the paper excellent in water absorption, and was excellent in storage stability is provided. Paper obtained using this paper softener is preferably used for sanitary thin paper such as toilet paper, dust paper, facial tissue, Kyoto flower paper, paper napkins, paper towels, wipers, sanitary paper, diaper paper, and the like.

Claims (3)

A softener for paper containing an alkylene oxide derivative (a) and at least one compound (b) selected from the group consisting of a quaternary ammonium compound (b1) and an amine compound (b2),
The alkylene oxide derivative (a) is a compound represented by the formula (1):
R ¹ O (AO) _x (BO) _y (AO) _z H (1)
Wherein R ¹ is an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an acyl group, A is an ethylene group, B is a butylene group, and 0 ≦ x ≦ 15, 1 ≦ y ≦ 5, (0 ≦ z ≦ 40, 15 ≦ x + z ≦ 40)
And
The softener for paper contains 1 to 20% by mass of (a) and 2 to 25% by mass of (b), and the mass ratio (a) / (a) / (b) A softener for paper, which is contained so that (b) is 1/10 to 5/1. The paper softener according to claim 1, wherein the quaternary ammonium compound (b1) is a quaternary ammonium salt represented by the formula (2) or a quaternary ammonium salt represented by the formula (3):

Wherein R ² and R ³ are each an alkyl or alkenyl group having 10 to 24 carbon atoms, R ⁴ is an alkyl or benzyl group having 1 to 3 carbon atoms, m is 1 to 10 and X ^- is an anion)

Wherein R ⁵ CO and R ⁶ CO are each an acyl group having 10 to 24 carbon atoms, R ⁷ , R ⁹ and R ¹⁰ are each an alkylene group having 1 to 3 carbon atoms, and R ⁸ Is an alkyl group having 1 to 3 carbon atoms or a benzyl group, and X ⁻ is an anion). The amine compound (b2) is obtained by reacting a carboxylic acid having 10 to 24 carbon atoms with a polyalkylene polyamine represented by the formula (4) in a molar ratio of 1.5: 1 to 2.5: 1. The paper softener according to claim 1, which is an amidoamine compound or a salt thereof:
_{^{NH 2 -R 11 - (NH-}} R 12) n -NH 2 (4)
(In the formula, R ¹¹ and R ¹² are each an alkylene group having 1 to 4 carbon atoms, and n is an integer of 1 to 3).